Although most of Japan lies in the temperate zone, the southern Ryukyu islands, which include the island of Okinawa, lie along the Tropic of Cancer and can range from tropical to sub-tropical in climate. Many of the native plants to the Ryukyu islands also are native to other nearby islands and can range as far south as the equator.
Sandanqua viburnum is native to Okinawa and other islands in the Ryukyu island chain. The Ryukyu islands are the southernmost islands of Japan, just northeast of Taiwan. This fast-growing, evergreen shrub can grow to between 4 and 12 feet if not pruned. This shrub has leathery, dark green leaves. It produces small, tubular white and pink waxy flowers. It will grow in many soil types but does best in well-draining, loamy soil with lots of organic matter. This plant does well in many light conditions ranging from partial sun to full shade. It requires regular watering. Keep the soil constantly moist.
Okinawan holly is an evergreen shrub native to Okinawa that flowers with white blossoms in mid-spring. The narrow leaves of this 24- to 36-inch tall shrub are small and dark green with shallow teeth. If a male Okinawan holly is within 100 feet of a female, the female shrub will produce small red berries in the fall. Okinawan holly requires full sun and does best in slightly acidic soil that drains well. Okinawan holly requires moist soil during the growing season but does best with dry soil after the fall to allow the bush to prepare for winter.
Fatsia japonica, or Japanese aralia, is native to Japan. This shrub can grow to 8 feet tall and sustain leaves as large as 12 inches. The Japanese aralia does best in fertile, loamy, well-draining soil that is slightly acidic. It requires shade to partial shade and does well in a north-facing location. The leaves of this plant grow on long stems. Sometimes, the weight of the leaves will cause the entire plant to lean to one side or another. Mature plants have clusters of white flowers on white stalks that may result in small, fleshy black fruit. Keep the soil moist but not wet.